Tuesday, August 21, 2012

Reader Question: Variation in Breastfeeding Frequency

Recently, a reader asked us why her 8-week-old baby was still nursing every 2 hours when her friend's baby (just a couple of weeks older) began nursing every 3 to 4 hours around the same age. Both babies are healthy, nursing well, and gaining the right amount of weight. In this post, we'll share some information about differences in how often moms breastfeed even when babies are the same age and size.

Differences in Moms and Babies

Because most breastfeeding moms don't see how much milk their babies get, they don't know how much milk volumes can vary from one mom to the next or even from feed to feed. Moms may assume that their babies take about the same amount of milk as their friends' babies but there can be big differences even when babies are about the same age. For example, breastfed babies take an average of about 27 oz per day from 1 to 3 months of age but that amount can vary from mom to mom by as much as 25%. Why so much difference? There are a few reasons why:
  • Moms vary in how much milk they can "store" in their breasts. The amount is limited by the milk producing structures that are in her breasts after lactation is established. Studies in Australian showed that this "storage capacity" can vary from just under 3 oz to over 20 oz! Moms also can have different storage capacity in one breast versus the other.
  • The fat content and the calorie content of milk also varies from one mom to the next. While the type of fat in mom's milk is affected by diet, the total fat and calories in milk are not. Total milk fat content is related to mom's biology and tends to be the same for all of her children. So, some moms make "2% milk" and some moms make "whole" milk and others are in between.
  • Babies vary in how much milk they need to take each day. Some grow very fast and some a little slower, some healthy babies are very big and others are smaller.
  • The amount of milk that babies can drink all at once also varies quite a bit. While all young babies have tiny stomachs, some are physically able to take more than other babies and others a little less.
Moms and Babies Work Together

When moms are responding to their babies' cues when feeding, most babies are good at taking as much milk as they need to get enough calories to be healthy and grow. But, since moms are also part of the picture, babies will differ in how often they need to feed based on mom's storage capacity and the calories in her milk. If a mom has higher fat milk, a big storage capacity, and a baby who can take a lot of milk at once, she can go longer between feeds (like the 3-4 hours for the friend in the story above). But, if she is a mom with a lower storage capacity, lower fat milk, and a smaller baby, she's going to need to feed more often so that her baby gets all the calories she needs (like every 2 hours). As babies get bigger, they will be able to take more milk at once and get closer to moms' capacities. They also build their own "storage" (baby fat) that helps them go longer between feeds.

If you are a worrier, you might be thinking that you'll end up with low fat milk and a small capacity combined with a bigger baby who can't take much milk at once. While that is possible, it's not common. Even then, a baby who nurses a lot gets a lot of practice and with a lot of practice, babies get very efficient (and quick) at nursing so the total time spent nursing may not differ much from moms who don't have to nurse as often.

References:
R.A. Lawrence. Breastfeeding: A Guide for the Medical Professional. Saunders, 2010.

Daly SE, Kent JC, Huynh DQ, Owens RA, Alexander BF, Ng KC, Hartmann PE. The determination of short-term breast volume changes and the rate of synthesis of human milk using computerized breast measurement. Exp Physiol. 1992;77:79-87.

3 comments:

  1. Thanks for this post. I've been trying to improve the quality of my milk by eating better and taking supplements like alfalfa, so I'm disappointed that the total fat and calories in my milk are determined by biology and not diet :-(

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  2. My son (now almost 1) nursed every 1.5 hours until he was about 4 months old, and every 3 hours around the clock until he was 9 months! Now at 11 months he can do a 5 or 6 hour stretch without it. :)

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  3. Im glad to know to that the quality of my milk is determined by genetics and not just my eating. No matter how much I would increase or eliminate from my diet it seemed my LO I was nursing didnt seem to notice a difference or show one. I hope this time I have enough fat storage for "whole" milk :)

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